title: Infancy-onset dietary counseling of low-saturated-fat diet improves insulin sensitivity in healthy adolescents 15-20 years of age: the Special Turku Coronary Risk Factor Intervention Project (STRIP) study.
abstract: OBJECTIVE
  We reported previously that low-saturated-fat dietary counseling started in infancy improves insulin sensitivity in healthy children 9 years of age. The aim of this study was to evaluate the effect of lifelong dietary counseling on insulin sensitivity in healthy adolescents between 15 and 20 years of age. In addition, we examined dietary fiber intake and the polyunsaturated fatty acid (PUFA)+monounsaturated (MUFA)-to-saturated fatty acid (SFA) ratio in the intervention and control adolescents and the association of these dietary factors with homeostasis model of insulin resistance (HOMA-IR).
  
  
  METHODS
  The study comprised adolescents participating in the randomized, controlled Special Turku Coronary Risk Factor Intervention Project (STRIP) study, which aims to guide the study participants toward a diet beneficial for cardiovascular health. HOMA-IR was assessed annually between 15 and 20 years of age (n=518; intervention, n=245; control, n=273), along with diet, BMI, pubertal status, serum cotinine concentrations, and physical activity. Dietary counseling was given biannually during the follow-up.
  
  
  RESULTS
  HOMA-IR was lower (7.5% on average) in the intervention group than in the control group between 15 and 20 years of age (P=0.0051). The intervention effect was similar in girls and boys. The PUFA+MUFA-to-SFA ratio was higher (P<0.0001) and the dietary fiber (g/MJ) intake was higher (P=0.0058) in the intervention group compared with the control group. There was no association between the PUFA+MUFA-to-/SFA ratio and HOMA-IR, whereas dietary fiber intake (g/MJ) was associated with HOMA-IR in girls (P<0.0001).
  
  
  CONCLUSIONS
  Dietary counseling initiated in infancy and maintained until 20 years of age was associated with improved insulin sensitivity in adolescents.
authors.affiliation: Corresponding author: Olli Oranta, olli.oranta@utu.fi.
authors.forename: Olli
authors.initials: O
authors.lastname: Oranta
authors.forename: Katja
authors.initials: K
authors.lastname: Pahkala
authors.forename: Soile
authors.initials: S
authors.lastname: Ruottinen
authors.forename: Harri
authors.initials: H
authors.lastname: Niinikoski
authors.forename: Hanna
authors.initials: H
authors.lastname: Lagström
authors.forename: Jorma S A
authors.initials: JS
authors.lastname: Viikari
authors.forename: Antti
authors.initials: A
authors.lastname: Jula
authors.forename: Britt-Marie
authors.initials: BM
authors.lastname: Loo
authors.forename: Olli
authors.initials: O
authors.lastname: Simell
authors.forename: Tapani
authors.initials: T
authors.lastname: Rönnemaa
authors.forename: Olli T
authors.initials: OT
authors.lastname: Raitakari
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose; D003376:Counseling / Q000379:methods*; D018752:Diet, Fat-Restricted; D004041:Dietary Fats; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D004041:Dietary Fats